Electrochemical routes for industrial synthesis - SciELO

(251 is MPT.) For those planning a career in chemistry. Modern concepts of molecular structure, mechanisms of organic reactions, and synthetic methods for organic compounds, including natural products. Concurrent registration in , required. Prerequisite: (MPT 251) ; (252) .

electrochemical synthesis, organic chemicals, ..

In any worthwhile comparison of the advantages of chemical vs ..

ZIF-8: A comparison of synthesis methods - ScienceDirect

The combination of the enzymatic and electrochemical methods with traditional synthetic techniques proved to be a powerful tool that, when applied to synthetic ventures, did result in more efficient and environmentally benign procedures.

ZIF-8 was prepared by 7 different synthesis methods

Different methods have been developed to obtain silver NPs of various shapes and sizes, including laser ablation, gamma irradiation, electron irradiation, chemical reduction, photochemical methods, microwave processing, and thermal decomposition of silver oxalate in water and in ethylene glycol, and biological synthetic methods. Biosynthetic methods of NPs provide a new possibility of conveniently synthesizing NPs using natural reducing and stabilizing agents. As possible environmentally and economically friendly alternatives to chemical and physical approaches, biosynthesis of metal and semiconductor NPs using organisms has been suggested. Monodispersity and particle size and shape are very important parameters in the evaluation of NPs synthesis. Therefore, the efficient control on the morphology and monodispersity of NPs must be explored. The reaction conditions should be optimized. By using screened organisms with high production capability and controlling the reaction conditions, well- characterized NPs can be obtained by synthesis rates faster or compatible to those of chemical and physical approaches. This eco-friendly method can potentially be used in various areas, including pharmaceuticals, cosmetics, foods, and medical applications.

Journal of Materials Chemistry A;

Microwave-assisted synthesis is a promising method for synthesis of silver NPs. Microwave heating is better than a conventional oil bath when it comes to consistently yielding nanostructures with smaller sizes, narrower size distributions, and a higher degree of crystallization (). Microwave heating has shorter reaction times, reduced energy consumption, and better product yields which prevents the agglomeration of the particles formed (). Moreover, other than the elimination of the oil bath, microwave-assisted synthesis, in conjunction with benign reaction media, can also drastically reduce chemical wastes and reaction times in several organic syntheses and chemical transformations ().

Comparison Between Electrochemical ..

Electrochemical synthetic method can be used to synthesize silver NPs. It is possible to control particle size by adjusting electrolysis parameters and to improve homogeneity of silver NPs by changing the composition of electrolytic solutions. Polyphenylpyrrole coated silver nanospheroids (3-20 nm) were synthesized by electrochemical reduction at the liquid/liquid interface. This nano-compound was prepared by transferring the silver metal ion from aqueous phase to organic phase, where it reacted with pyrrole monomer (). In another study, monodisperse silver nanospheroids (1-18 nm) were synthesized by electrochemical reduction inside or outside zeolite crystals according to silver exchange degree of compact zeolite film modified electrodes (). Furthermore, spherical silver NPs (10-20 nm) with narrow size distributions were conveniently synthesized in aqueous solution by an electrochemical method (). Poly N-vinylpyrrolidone was chosen as the stabilizer for the silver clusters in this study. Poly N-vinylpyrrolidone protects NPs from agglomeration, significantly reduces silver deposition rate, and promotes silver nucleation and silver particle formation rate. Application of rotating platinum cathode effectively solves the technological difficulty of rapidly transferring metallic NPs from cathode vicinity to bulk solution, avoiding the occurrence of flocculates in vicinity of cathode, and ensures monodispersity of particles. Addition of sodium dodecyl benzene sulfonate to the electrolyte improved particle size and particle size distribution of silver NPs ().

29/01/2013 · In the electrochemical synthesis ..

The most common approach for synthesis of silver NPs is chemical reduction by organic and inorganic reducing agents. In general, different reducing agents such as sodium citrate, ascorbate, sodium borohydride (NaBH4), elemental hydrogen, polyol process, Tollens reagent, N, N-dimethylformamide (DMF), and poly (ethylene glycol)-block copolymers are used for reduction of silver ions (Ag+) in aqueous or non-aqueous solutions. These reducing agents reduce Ag+ and lead to the formation of metallic silver (Ag0), which is followed by agglomeration into oligomeric clusters. These clusters eventually lead to the formation of metallic colloidal silver particles (,,). It is important to use protective agents to stabilize dispersive NPs during the course of metal nanoparticle preparation, and protect the NPs that can be absorbed on or bind onto nanoparticle surfaces, avoiding their agglomeration (). The presence of surfactants comprising functionalities (e.g., thiols, amines, acids, and alcohols) for interactions with particle surfaces can stabilize particle growth, and protect particles from sedimentation, agglomeration, or losing their surface properties.